Crown control for rolling mills

ABSTRACT

IN A FOUR HIGH ROLLING MILL COMPRISING CROWN CONTROL MEANS FOR BENDING THE WORK ROLLS THE FORCES ENGAGING AT THE CHUCKS OF THE WORK ROLLS ARE CONDUCTED OVER PAIRS OF BEAMS EXTENDING ON BOTH SIDES OF THE CHUCKS AND HAVING LUGS REACHING BEHIND PROJECTIONS OF THE CHUCKS. THE LUGS MOVING THE WORK ROLLS.

Oct. 5, 1971 PILLQN 3,610,013

CROWM CONTROL FOR ROLLING MILLS Filed July 14, 1969 2 Sheets-Sheet l Oct. 5, 1971 H. PILLON 3,610,013

CROWM CONTROL FOR ROLLING MILLS Filed July 14, 1969 2 Sheets-Sheet 2 United States Patent US. Cl. 72-238 6 Claims ABSTRACT OF THE DISCLOSURE In a four high rolling mill comprising crown control means for bending the work rolls the forces engaging at the chucks of the work rolls are conducted over pairs of beams extending on both sides of the chucks and having lugs reaching behind projections of the chucks. The lugs constitute simultaneuosly interrupted slide rails for removin the work rolls.

BACKGROUND OF THE INVENTION The invention relates to a rolling mill for rolling fiat materials such as plates, strips and sheets with crown control means for bending at least the work rolls whose outer chucks are engaged by hydraulic bending devices which generate counter bending moments to equalize the deviations from a straight line by the jacket lines of the work rolls produced in the rolling gap during operation. In the case where the work rolls bear on additional intermediate or support rolls the chucks of the bent work rolls are subjected to the forces while in the other case the bending forces are exerted through additional outer chucks on the extended roll necks of the work rolls.

According to the known arrangements for providing a crown control of the work rolls by means of hydraulic bending devices the bending cylinders of such prior art crown control arrangements are set either into the work roll chucks and operate as expansion devices designed for the crown control, or the cylinders are mounted on the stands and connected over their piston rods with the chucks or outer bearing members so as to be easily detachable for removing the work rolls laterally without wasting any time.

To provide a rapid exchange of work rolls it is known to introduce slide rails in the frame or to set down the work rolls on rails provided in the frame. The work rolls are taken out over these slide tracks or rails usually in a super-imposed secured position simultaneously. With respect to the crown control it is necessary according to the existing state of the art to disconnect hydraulic lines when the bending cylinders are mounted in the chucks or the piston rods of the bending cylinders must be disconnected from the chucks or the outer bearing members when the bending cylinders are connected to the stands, which is preferable because in such an arrangement the cylinders are located outside the rolling gap and are protected against scale and spray water or cooling and lubricating means.

SUMMARY OF THE INVENTION It is an object of the invention to accelerate the dismounting and the mounting of work rolls or of the only rolls of a rolling mill provided with an hydraulic crown control for these rolls while employing conventional slide rails in the frame for taking over the work rolls.

The invention consists essentially in that the bending devices engage on pairs of beams extending on both sides of the bearing members and disposed for vertical movement in the window openings of the stands, the pairs of beams guiding the bearing members of the rolls laterally,

Patented Oct. 5, 1971 ice and each beam having a nose reaching behind projections of the bearing members for transferring the bending forces to the bearing members and are designed simultaneously as interrupted slide rails for the lateral dismounting of the work rolls taken over by the slide rails.

In this manner it is obtained that during the exchange of the work rolls no connections of any kind, either mechanical or hydraulic, need be disconnected since the bending forces are conducted through the beams and since due to the close interfitting between the beams and bearing members the flexing beams designed as slide rails may remain in the frame. The bending devices may be arranged for expansion between the pairs of flexing beams but it is preferable, particularly in plate or heavy sheet rooling mills, to mount the bending cylinders on the stands vin order to locate them out of the range of the rolling gap.

The work rolls are appropriately moved out together and in this case only the lower pair of beams must have slide rails by means of which the set of rolls is lifted up to a stop or an abutment shoulder by actuating the bending cylinders engaging at the lower beams. In the stop position the slide rails are in line with the transfer tracks which may be rolled laterally against the frame.

In the event that for a four-high frame comprising support rolls for the work rolls the support rolls are to be exchanged it is necessary to move out at least the upper beams. For this reason alone the connections between the beams and the bending devices which engage them are arranged for easy release. During the exchange of the support rolls the entire set of rolls together with the upper disconnected flexing beams are moved out laterally.

It is already known to airange the piston rods of the bending cylinders so that they may be easily disconnected and this does not constitute any particular problem. For this reason the cylinders for the upper and lower work rolls could be secured in a similar manner on the stand parts. According to the present invention it is no longer necessary to disconnect the piston rods during the exchange of the work rolls from the beams, and therefore they could disturb on the dismount side of the stand the discharge movement of the lower work rolls. On the driving side of the piston rods of the lower flexing device could interfere with the lower driving spindle. In order to avoid these difliculties the lower beams are provided with openings at their extremities which project outwardly beyond the stands and roller type lever arms of two-arm levers mounted on the stands reach into these openings while their other lever arms are connected to the piston rods of hydraulic bending cylinders. The bearing blocks of the two-arm levers may be guided for sliding movement on the stands cross-wise of the openings or may be secured in position.

In this manner the roller type heads of the levers may be moved laterally out of openings or breaches of the flexing beams when they are to be dismounted also during an exchange of support rolls.

The bending devices for the upper beams are secured appropriately at stand parts which follow the screwdown movements of the upper roll or rolls, for example, on level adjustable stand caps of a tie rod rolling stand. In this manner it is obtained that the work stroke of the bending cylinders may be kept small and that the bending forces do not exert a stress on the screwdown devices.

The beams according to the invention operate not only to transfer to the work roll bearing members, if necessary in both possible directions, but function also as slide rails for the roll exchange and may constitute according to a further proposal of the invention supports for rolling mill fittings, such as scraper tools and devices 3 for supplying the spray-water, the cooling medium and the lubricant, and they assume thus a triple function. The pressures exerted by the scraper tools produce moments in the beams which oppose those generated by the bending forces and thus avoid maximum bending stresses in the beams.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of a rolling mill comprising a crown control arrangement according to the invention is shown inthe accompanying drawings in which:

FIG. 1 is a front elevational view of the rolling mill in the rolling direction with the work rolls removed and,

FIG. 2 is a side elevational view of the frame partially in section to illustrate the two-arm bending lever.

DESCRIPTION OF THE PREFERRED EMBODIMENT The rolling stand consists of two U-shaped stand supports 1 and 2 with vertically adjustable stand caps 3 and 4 which are coupled under tension by means of tie rods not shown. These stand supports 1, 2 are connected through a girder 5 and the stand caps 3, 4 through a girder 6. The lower stand supports 1, 2 supported on sole plates 7 are mounted below on a rigid girder 8 which carries at 9 and 10 hydraulic bending cylinders 11, 12 for pivotal movement whose piston rods 13, 14 engage on opposite necks a, 16a of bearing members 15, 16 which in turn are fitted around the extended necks of the lower support roll 17. In FIG. 2 only one bending cylinder 11 of a pair of bending cylinders is shown which are disposed on both sides of the frame. One recognizes also in FIG. 2 that the bending cylinders may be pivoted laterally as shown in dotted lines so that the bearing eyes 13a, 14a of the piston rods 13, 14 may be pulled off the opposite necks 15a, 16a when the lower support roll 17 and the chucks 18, 19 are to be dismounted laterally.

For the upper support roll 20 bending cylinders 21, 22 of similar construction are pivotally mounted on the upper girder 6 and engage in a similar manner on extended roll necks of the support roll 20. The upper support roll 20 is mounted in chucks 23, 24 which are supported at 23a (FIG. 2) on the stand caps 3, 4. The bending cylinders 21, 22 for the upper support roll 20 provide also a balancing of this roll and its chucks.

In the illustrated four-high rolling mill frame not only the support rolls 17, 20 are controlled with respect to their crown but also the work rolls 25, 26, which are shown in FIG. 1 as laterally dismounted. As may be seen from FIG. 2 their chucks 27, 28 are guided in pairs of beams 30 or 31 laterally, which in turn are guided inside the window openings of the lower stand parts 1, 2 for vertical movement. These pairs of beams 30, 31 extend from one lower stand part to the other and carry lugs 30a or 31a which reach behind projections of the work roll-chucks 27, 28 in the direction of the bending forces which have tobe generated and which are directed diametrically to the rolling gap to provide the crown control. The arrows indicated in FIG. 2 and originating at the lugs 30a or 31a indicate the direction of the bending forces by which the work rolls 25, 26 may be brought over their entire length into contact with the crown controlled support rolls 17, 20. The lower beams 31 for the chucks 28 of the lower work roll 26 have further lugs 31b which constitute the slide rails for removing a set of work rolls.

In order to explain the manner in which the bending forces engage at the beams 30, 31 reference is made to the upper pair of beams 30 shown in FIG. 1. It can thus be seen that the upper beams 30 project laterally beyond the lower stand parts 1, 2 and are connected at the ends by bolts 32, 33 (see also FIG. 2, right half) which engage pairs of tie rods 34, 35 of the upper bending cylinders 36, 37 for the upper work roll. As in FIG. 2 only one bending cylinder 21 of a pair of bend- .4 ing cylinders is shown for the upper support roll 20 there is shown only one bending cylinder 36 of a cylinder pair for the upper flexing beam pair 30. The bending cylinders 36, 37 which may also be used together as two individual cylinders are connected over links 38, 39 to the upper girder 6. When a load is exerted on the bending cylinders 36, 37 the tie rods 34, 35 pull the upper flexing beams 30 upwardly whereby the bending forces are transferred over the lugs 30a to the chucks 27 of the upper work roll 25.

The lower flexing beams 31 could be connected in the same manner to bending cylinders which exert a downward pull but this is not suitable at the driving side of the frame. The construction for generating downwardly directed bending forces for the lower work roll 26 may be seen in FIG. 2. A pair of bending cylinders 40 on the driving side of the frame which are fixed to the one lower stand part 1 and engage at 41 a pair of two-arm levers 42. These two-arm levers 42 are pivota bly mounted on swing bolts 43 which are mounted in slotted bearing blocks 44. Each lever 42 has a short roller type lever arm 42a which engages a breach 31c of flexing beam 31. When the piston rods 40a of the bending cylinders 40 move upwardly the roller type lever arms 42a and thus also the flexing beams 31 move downwardly and force through their lugs 31a the chucks 28 of the lower work rolls 26 downwardly. In this manner the lower work roll 26 is pressed on its entire length against the lower support roll 17 whichever crown this latter may have. The improved friction contact between the driven work rolls and the support rolls is particularly significant during the reversing operation of a heavy sheet four-high rolling frame.

The bearing blocks 44 are mounted cross-Wise of the breaches 310 of the lower flexing beams 31 for sliding movement on the lower stand parts 1, 2 and may be fixed in position. In this manner the swing bolts 43 amy be moved outwardly so that the roller type lever arms 42a move out of the breaches 310 of the lower flexing beams 31 in order to permit their removal.

The dismounting of the work rolls is carried out in the following manner:

To begin, the upper set of rolls, namely the support roll 20 together with the upper Work roll 25, are raised by means of the screwdown device of the frame until between the work rolls-chucks 27, 28 spacer members may be inserted. Thereafter the double acting bending cylinders 40 are actuated so that the piston rods 40a move downwardly and the roller type lever arms 42a of the double arm levers 42 move the lower flexing beams 31 upwardly. In this manner the slide rails 31b of the lower flexing beams 31 abut against the chucks 28 of the lower work roll and lift the chucks 27 of the upper work roll 25 over the inserted spacer elements from the lugs 30a of the upper flexing beams 30. In this way the entire set of work rolls rests merely on the lugs or slide rails 31b of the lower flexing beams 31. The lifting stroke of the flexing beams 31 is limited by a stop which is not shown in detail, and therefore the slide rails 3111 take up an exactly defined vertical position which coincides with transfer tracks 50 arranged beside the frame. After releasing an additional locking device between the flexing beams 30, 31 and the work roll-chucks 27, 28 which is not shown in the drawing the work roll set is moved out in a known manner laterally over the slide rails 31]) on to the transfer tracks 50. Subsequently the work rolls are taken away successively by means of a crane with crane gear 51. The beams 30, 31 remain in the frame during the work roll exchange so that at most the connections for the bearing lubrication of the work rolls need be disconnected.

The mounting of work rolls is carried out in the reverse order. To remove a complete set of rolls including the support rolls 17, 20 additional transfer tracks 52 are provided laterally adjacent the frame which are located lower wil il Uflllfifer tracks 56 which are removed during the dismounting of a complete set of rolls. Below the chucks 18, 19 of the lower support roll 17 extend dismounting tracks 53 which may be pulled out of the frame by means of a chain drive 54.

After the lower support roll 17 has been lifted by means of the double acting bending cylinders 11, 12 or by carriages which reach under the support roll in order to remove shims which determine the height of the rolling gap, the chucks 18, 19 are set down on the dismounting tracks 53. Thereafter spacer members are placed between the chucks 18, 19 and the chucks 28 of the lower work roll and further between the pairs of chucks of the work rolls. Further spacer members are inserted between the chucks 27 of the upper work roll 25 as well as the chucks 23, 24 of the upper support roll 20 for which purpose previously the piston rods 34, 35 of the bending cylinders 36, 37 for the upper flexing beams 30, 31 are pivoted laterally away from their connector bolt 32. When subsequently the screwdown device is actuated in order to raise the support rolls-chucks the work rolls-chucks 27 remain in position.

After all superimposed chucks have been fixed relative to each other by spacer members beside the piston rods 34, 35 and the piston rods of the main bending cylinders for the support rolls have been swung out laterally the set of rolls resting on the dismounting tracks 53 may be removed laterally. The upper beams 30 are not moved out during this operation and for this purpose the spacer members inserted between the work rolls-chucks 27, 28 are provided with an outward projection which is sufficient to support also the beams 30 interconnected through the two bolts 32.

I claim: 1. A rolling mill, comprising: a stand provided with spaced openings; at least two rolls, chucks mounting said rolls for rotation and means supporting said chucks from said stand for vertical movement within said openings;

beams associated with said rolls including portions thereof extending laterally of said rolls, said beams being provided with lugs encompassing portions of said chucks supporting said rolls while permitting said rolls to slide therealong; means adjusting the position of said beams to impart bending forces to said rolls through said chucks compensating for deflection in said rolls; and

additional support rolls engaging said two rolls, chucks mounting said support rolls for rotation and means securing said chucks to said stand.

2. A rolling mill as in claim 1, including a trackway positioned adjacent said stand for transporting said rolls to and from the rolling mill, and means stopping said beams when said lugs are in juxtaposition with said trackway permitting removal of said rolls along said lugs onto said trackway.

3. A rolling mill as in claim 1, said rolls comprising an upper and a lower work roll and said beams comprising an upper and a lower beam adjacent said upper and lower work rolls, respectively, said means adjusting the position of said beams including hydraulic cylinders mounted on said stand, piston rods, means actuating said piston rods by said cylinders, bearing blocks, means slideably mounting said bearing blocks on said stand, levers, means pivotably mounting said levers to said bearing blocks, means connecting first arms of said levers to said piston rods, breaches provided at the extremities of said lower beam, said levers including second arms extending into said breaches such that as said hydraulic cylinders are actuated said lower beam is moved downwardly forcing said chucks associated with said lower work roll downwardly.

4. A rolling mill as in claim' 3, wherein said means adjusting the position of said beams further includes second hydraulic cylinders mounted on said stand, second piston rods, means actuating said second piston rods by said second hydraulic cylinders and means connecting said second piston rods and said upper beam.

5. A rolling mill as in claim 4, said stand including caps, means vertically adjusting said caps in relation to the remainder of said stand, said second hydraulic cylinders used to adjust the position of said upper beam being supported by said caps.

6. A rolling mill as in claim 5, including supports formed as a part of said upper and lower beams for rolling mill fixtures such as scraping tools and devices for supplying spray water, cooling medium and lubricating means.

References Cited UNITED STATES PATENTS 2,985,042 5/1961 Talbot 72245 X 3,171,305 3/1965 Stone 72245 X 3,373,588 3/1968 Stone 72-245 X TRAVIS S. MCGEHEE, Primary Examiner US. Cl. X.R. 72245 

